import React, { Component } from 'react'
import { sum, mul } from './utils'
export default class App extends Component {
  constructor() {
    super()
    this.state = {
      counter: 0
    }
  }
  render() {
    return (
      <div>
        <h2>
          当前计数: {this.state.counter}
        </h2>
        <button onClick={() => this.sum()}>+</button>
        <button onClick={() => this.mul()}>*</button>
      </div>
    )
  }
}